Treating rails.



EDWARD F. xnmvnv, or wn'srmon'r BOROUGH, PENNSYLVANIA.

TREATING RAILS.

No Drawing.

To all whom it mag concern Be it known that I, EDWARD-F. KENNEY,

a citizen of the United States, residing in the borough of Westmont, in the county of Cambria and State of Pennsylvania, (whose post-office address is Johnstown, Pennsylvania,) have invented certain new and useful Improvements in Treating Rails; and

- I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to treating steel rails and similar articles after they have been rolled or otherwise formed, for the purpose of making them stronger, tougher and better adapted to withstand the shocks, impacts and wear to which they are subjected when in use. In order to accomplish this in a simple, economical and practical way and one which will be commercially available, I prefer to quench the rails in water, oil or other cooling medium after they have been rolled or otherwise formed and while they are still at the proper heat forthis purpose, in order to avoid the necessity and expense of reheating them before quenching. In certain cases, however, I may permit the rails to cool to atmospheric, or

similar temperatures, after they have been 7 rolled and then reheat them to the proper temperature for quenching, as I can obtain thereby, equivalent results, but at the expense of a slight additional cost and loss of time.

In order that the rails or othermaterial shall not be badly warped by reason of the cooling and the shrinking of the thinner portions, or those with a greater surface as compared with their volume before the shrinkage of the other and more massive portions, I prefer to deliver them into the cooling bath when they are in a vertical position, or a position slightly inclined from thevertical, in which casethe only warpin that will be produced is that due to the ference in cooling of the thinner and thicker portions. If, on the other hand, the rail or other material is supported horizontally or approximately so on supports of any kind, itwill warp and bend, due to its weight on these supports in addition to the warping dueto unequal shrinkage of its diflerent portions, andthis will make it impossible or impracticable to straighten and if S .ecification of Letters Patent.

Application filed March 2c, 1916. Serial No. 85,479.

Patented Nov. 28, 1916.

attempted will set up undue stresses. In addition to this, I have found that it is not necessary to cool or quench the rail or' other material to atmospheric temperature or to that of the cooling medium if at or near atmospheric temperature; but that by cooling it to a lesser extent, I prevent undue shrinkage stresses and cracks. I have also found that rails and other materials which have been quenched and annealed and allowed to cool to approximately atmospheric temperature or that of the cooling medium at or near atmospheric temperature are too hard to straighten without danger of damage, which in their further use would be very disastrous.

,In order to obviate setting up of undue stresses after the rails have been quenched, I prefer to straighten them when at a considerable temperature and one at which they are sufiiciently plastic to be straightened either by a straightening press or a. set of rolls; but this temperature is one which will not affect the amorphous structure produced by the quenching. c

Although my invention may be carried out through various ranges of temperatures, I prefer to proceed about as follows, and in order to simplify the language I will refer to temperature on the Fahrenheit scale and to rails alone, although other steel material may be similarly treated, as will be readily understood: I first roll the rails in a rolling mill from a white heat and finish them in the mill at temperatures varying from 1400 degrees to 2000 degrees.

After the rail has issued from the mill and a very-short time elapsed, it is turned upward preferably while resting on supports distributed throughout its length into a ver-' tical or inclined position while it is at a temperature from about 1350- degrees to 1900 degrees, and it is then lowered and cooled in a bath of cold, warm or hot que iching material, either water, oil or other medium as may be desired. This at once provides an amorphous or very fine str ":ture in the steel and one which puts the 'aaterial in. condition 'to withstand shocks", impacts and wear of use. This quenching is accomplished rapidly, and the material is withdrawn from the bath before its temperature falls below about 400. degrees. I may, however, as previously stated, allow the rails to cool after rolling and then reheat themprior to quenching, instead of which .this method avoids undue temperaneals the-material andremovestemperature fine or amorphous structure thereo I then immediately straighten the rail in rolls or quenching at their finishing hr residual heat. In. this method of cooling the structure is held and maintained amorphous on of fine grain, while avoiding cooling down to ordinary atmospheric temperatures and the steel material is more plastic, besides str'esses without materially chan ing the a gag press when its temperature is ape proximately from 600 degrees to 950 do; grees. At these temperatures the material s much more plastic and its elastic limit, much less than if at atmospheric tempera-, ture, and will thus permit straighteningwithout causing undue stresses or strains. t The critical temperature or i-recalescent pointior steel rails is about 1250 degrees,

and I take pains not 'tojexceed this in reheating the rails prior to the proposed annealing actual tests of rails treated infthis'way jshow that the elasticlimit is very much increased,

the ultimate strength is" considerably inincreased, the elongation is aboutthe same, the

reduction of area is v'ery largely increased, hardness, and consequent wearing qualities 7 ares-{increased 'very much, the bendlng ,strength and capacity is almost doubled, the .resistance to impactis almost doubled, and

lthlresistance to the drop test is considerably increased, together with an increase the ductility and stiffness. In straightening the rails in this manner at the temperature lfstated, I take palnsto give them a-slight zcurvature so that when they'are cold they -will draw substantially straight.

Although I have shown'and described my mprovements 1n considerable detail, I do not Wish to be limited to the exact and specific details shown and described, but may use such substitutions, modifications or equivalents thereof as are embraced within the scop'enof my invention, or as pointed out in thefclaims, I

Havingfthus described my invention, What I claim and desire to secure by Letters Patent is V i 1. The steps in themetliod oftreating rails, which consists in quenching them in a vertical 'or slightly inclined position and thereby cooling them to a temperature not less than 4:00 degrees. 2. The, steps in the process of treatin finishing temperature to a temperature not from 1400 degrees to 2000 degrees, then quenchingthem to a temperature not. less than 400 degrees, then reheating them to temperatures above 800degrees, but not more than their recalesoent temperature, then straightening them before they are at a temrature of less than .600 de ees. before straightening them; g-Thegesults of i' gr rails comprising quenching them at their I less than 400 degrees, then heating them to 7 4:.The steps in the method of treating .slightly inclined positionand thereby cooling them to a temperature. not less than about 400 degrees; t

5; The process offtreating rails, which consists in] heating them to temperatures horn-1400 degrees to 2000 degrees, then quenching them to a temperature not less than- 400 degrees, then reheating them to vf temperatures above 800 degrees, but not more than their recalescent temperature," then straightening them before they are at "a temperature of less than 600 degrees.

, In testimony. whereof I hereto aflix my signature.'-

EDWAR VF. 'KENNEYL' 

